This invention relates to DC circuit systems and particularly to thyristor circuits.
It is known in the prior art that thyristors, which are used as electronic switches in DC circuit systems, are easily triggered but difficult to block. Reverse blocking must be done with a high power current pulse which has the duration of the thyristor settling time and which absorbs the full power of the thyristor current rendering the thyristor currentless. Generally, the power pulse originates from a suitable capacitor which might be switched into the main thyristor circuit for blocking purposes.
The present invention eliminates the need for a plurality of capacitors and power sources where a number of thyristor circuits are involved. The power pulse for all thyristors is drawn from a common circuit arrangement with a DC power output and a switching transistor. Auxiliary thyristors may be provided for double-pole locking.